Here the link to the changelog on the specs:

 
   <h5>Video and audio codecs for <code>video</code> elements</h5>
 
   <p>User agents may support any video and audio codecs and container
   formats.</p>
 
-  <p>User agents should support Ogg Theora video and Ogg Vorbis audio,
-  as well as the Ogg container format. <a
-  href=”#refsOggTheora”>[THEORA]</a> <a
-  href=”#refsOggVorbis”>[VORBIS]</a> <a href=”#refsOgg”>[OGG]</a></p>
-  <!– (it’s not a MUST because some vendors may have legal reasons
-  why they can’t or won’t support it, and there’s no point making them
-  non-conforming when they have no choice in the matter) –>
+  <p class=”big-issue”>It would be helpful for interoperability if all
+  browsers could support the same codecs. However, there are no known
+  codecs that satisfy all the current players: we need a codec that is
+  known to not require per-unit or per-distributor licensing, that is
+  compatible with the open source development model, that is of
+  sufficient quality as to be usable, and that is not an additional
+  submarine patent risk for large companies. This is an ongoing issue
+  and this section will be updated once more information is
+  available.</p>
 
   <!– XXX mention that this spec doesn’t require native support or
   plugin support, either is fine –>
 
   <p class=”note”>Certain user agents might support no codecs at all,
   e.g. text browsers running over SSH connections.</p>

(X)HTML5 Tracking